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591.
H. Jonsson K. Viken Sandnes D. Schiedek R. Schneider B. E. Grsvik A. Goksyr 《Marine environmental research》2004,58(2-5):655
In an attempt to learn more about the cytochrome P450 (CYP) system of mussels, we used protein databases and alignment software to extract highly conserved CYP sequences. From these alignments synthetic peptides were produced and used for rabbit immunisation, which yielded polyclonal antibodies against the CYP families 2 and 4. The antibodies were evaluated with Western Blot and ELISA assays, using digestive gland microsomal samples from the mussel Mytilus edulis. Western Blots revealed immunoreactions for both antibodies. The anti-CYP2 sequence rendered one major immunopositive protein of ≈49 kDa size, and weak signals for proteins of ≈41 and 56 kDa size. The anti-CYP4 sequence rendered two major bands of ≈56 and 59 kDa size, and also a weak immunoreaction with a protein of ≈43 kDa size. ELISA rendered only weak signals even with a 1:50 dilution of IgG-purified serum. A 10-day exposure to Aroclor 1254 did not appear to affect any of the immunopositive proteins, while total PCBs in soft bodies increased from 14–40 ng/g DW in controls to 373–638 ng/g DW in exposed mussels. 相似文献
592.
E. García-Luque T. A. DelValls C. Casado-Martínez J. M. Forja A. Gmez-Parra 《Marine environmental research》2004,58(2-5):671
We describe the effect of heavy metals Zn, Cd, Pb and Cu on the induction of methallothioneins on the clam Scrobicularia plana along a salinity gradient simulated under laboratory conditions. The clams were exposed to constant heavy metal concentrations in a dynamic estuary simulator during a 15-day assay to investigate possible induction of metal-binding proteins in them. The concentration of heavy metals in water was analysed. Clams were analysed for methallothionein concentrations. The speciation of Zn, Cd, Pb and Cu along the salinity gradient was modelled. Zn showed the highest concentrations and its prevalent species was the free ion. Intersite differences have been observed in methallothionein concentration and related to the salinity gradient. It seems that synthesis of methallothioneins is the result of physiological forces acting in concert with the changes in the chemical speciation of metals, owing to the trace metals uptake is controlled by means of an interaction of physiology and physicochemistry. 相似文献
593.
Abstract. Eupolymnia nebulosa (Terebellidae) and Hermodke carunculata (Amphinomidae) were compared with respect to rates of oxygen consumption in response to acute temperature and salinity variation. E. nebulosa , but not H. carunculata , demonstrated significant temperature sensitivity correlating with the former species' restriction to habitats that are temperature variation. In contrast, H. carunculata occurs where such fluctuation is common. Oxygen uptake in both species was responsive to dilution of the medium whereas only H. carunculata demonstrated insensitivity to increased salinity under most temperature conditions. 相似文献
594.
Linearized water wave theory is used to show that a submerged long circular cylinder suitably constrained by springs and dampers to make small harmonic oscillations, can be extremely efficient in absorbing the energy in an incident regular wave whose crests are parallel to the axis of the cylinder. Experimental results are described which confirm the theory for small amplitude waves and which suggest that the device can still be fairly efficient in waves of moderate amplitude. 相似文献
595.
It has been known that the axisymmetric Cauchy–Poisson problem for dispersive water waves is well posed in the sense of stability. Thereby time evolution solutions of wave propagation depend continuously on initial conditions. However, in this paper, it is demonstrated that the axisymmetric Cauchy–Poisson problem is ill posed in the sense of stability for a certain class of initial conditions, so that the propagating solutions do not depend continuously on the initial conditions. In order to overcome the difficulty of the discontinuity, Landweber–Fridman's regularization, famous and well known in applied mathematics, are introduced and investigated to learn whether it is applicable to the present axisymmetric wave propagation problem. From the numerical experiments, it is shown that stable and accurate solutions are realized by the regularization, so that it can be applicable to the determination of the ill-posed Cauchy–Poisson problem. 相似文献
596.
Page DS Boehm PD Brown JS Neff JM Burns WA Bence AE 《Marine environmental research》2005,60(4):422-436
Polycyclic aromatic hydrocarbons (PAH) were measured in mussels (Mytilus trossulus) collected between 1990 and 2002 from 11 sites on the shores of Prince William Sound (PWS), Alaska, that were heavily oiled by the 1989 Exxon Valdez oil spill (EVOS). This study, utilizing the methods of the NOAA Status and Trends Mussel Watch Program, found that concentrations of PAH released from spill remnants have decreased dramatically with time and by 2002 were at or near the range of total PAH (TPAH) of 3-355 ng/g dry weight obtained for mussels from unoiled reference sites in PWS. Time-series TPAH data indicate a mean TPAH half-life in mussel tissues of 2.4 years with a range from 1.4 to 5.3, yielding an annual mean loss of bioaccumulated TPAH of 25%. The petroleum-derived TPAH fraction in mussel tissues has decreased with time, reflecting the decreasing release of EVOS residues in shoreline sediments. These results show that PAH from EVOS residues that remain buried in shoreline sediments after the early 1990s are in a form and at locations that have a low accessibility to mussels living in the intertidal zone. 相似文献
597.
The need for building human and institutional capacity has been identified in Agenda 21 of the UNCED conference as well as by a number of international environmental institutions as essential for integrated coastal management (ICM) and sustainable development in developing coastal states. There is a growing need for coastal management practitioners and organizations with expertise in planning and implementation for ICM. The application of strategies for institutional development and building human capacity in coastal management and other fields shows that short-term intensive training efforts and long-term institutional strengthening programs are appropriate to address the issues and needs of ICM. An overview of the experience of the URI/USAID International Coastal Resources Management Program in Sri Lanka, Thailand and Ecuador presents lessons learned for strengthening ICM efforts in developing countries. 相似文献
598.
Near-bottom normal incidence acoustic reflection data and sediment physical property data are used to study the relationships between acoustic reflections and sediment physical properties. A pinger-hydrophone experiment was performed to obtain the necessary acoustic reflection data. In addition, a standard piston core was retrieved in the acoustic survey area for physical property analysis. The piston core was sampled and 13 properties were measured at 55 locations within the top 12 m of the core. Correlation studies amongst the sediment physical properties resulted in the following strong correlations: acoustic impedance () and porosity (), (0.96); water content () and , (0.95); bulk density () and , (0.99).The empirical orthonormal function (EOF) method was employed for acoustic signal analysis. This method assumes no a-priori models of the sediment or causality. The EOF method reduced the acoustic data to 8 functions that contained 97.6% of the sample variance. The EOFs were subsequently analysed by using cepstrum analysis which reveals time delay information and enhances detecting zones of reflectivity. The result of the sediment physical property and cepstrum analysis indicates that zones of reflectivity are essentially zones of relatively high acoustic impedance, low porosity, and low phi (high mean grain size). 相似文献
599.
Concentrations of suspended matter and particulate cadmium,copper, lead and zinc in the Indian sector of the antarctic ocean 总被引:1,自引:0,他引:1
The concentrations of suspended matter and particulate Cd, Cu, Pb and Zn were determined for 36 samples collected at 6 stations in the Antarctic Ocean during December, 1970 and January, 1971 using membrane filters. The concentration of suspended matter was determined gravimetrically and trace metal levels were determined using anodic stripping voltammetry. For waters deeper than 100 m the concentration of suspended matter was < 100 μg l?1. Concentrations up to 542 μg l?1 were recorded between surface and 100 m. Individual concentrations of the metals were scattered with depth. Average concentrations of particulate metals were: Cd, 3.5 ng l?1; Cu, 100 ng l?1; Pb, 35 ng l?1; and Zn, 230 ng ;l?1 These measurements represent non-steady state conditions of early Antarctic summer as the ice pack disintegrates and biological activity increases. 相似文献
600.
The bacterial populations of mangrove swamps of Killai backwaters (11°21–11°29N, 79°46–79°50E, South India) were studied during August 1968 (Pre monsoon period) and December (post monsoon period). The presence of these groups such as agar digesters, algin digesters, cellulose digesters, sulphate reducers etc., bring about transformation of organic matter in the mangrove swamps. The presence of denitrifiers in mangrove swamps and in association with the molluscs may bring about the precipitation of calcium carbonate by removing the acid radicals such as sulphate and nitrite, increasing alkalinity. The luminiscent bacteria such asVibrio andAeromonas were also isolated in mangrove swamps of Killai backwaters. The iron bacteria likeLeptothrix sp. andGallionella sp. were also isolated from mangrove swamps of Killai backwaters. 相似文献